Process for recovering elemental sulfur from sulfur-gases.



W. F. LAMOREAUX & C. W. RENWICK. rnocass ron necovsmwc ELEMENTAL SULFUR mom suu un GASES.

APPLICATION FILED JUNE 21. [913.

Patented y 18, 19-15.

! 9 3 ,Zam. cream/a 22 nnrrnn ere. W est orricn WHATE FRANCIS LAMQEEAUK RFD GHAZREES win-mere fl-E :5 W- K, @E ISABELLA,

'TnNNESiSEE i otented May 38, 19155.

To (ZZZ whom it may concern Be it known that we, F. Lentonnanx, a citizen of the United States, end QHABLES W. Enuwrcn, a subject of Great Britain, both residing at lsahella, in the coimty of Folk and State of Tennessee, have invented new and useful Process for Becovering Elemental Sulfur from Sulfur- Gases, 01 which the following is a specification.

Ciu-r invention relates to an improved process or method of recovering sulfur from gases and the objects or" our improvement are first, to Introduce practically elemental sulfur from cxirls or other compounds of sulfur such as are contained in variable admixture with in the gases generated by or liberated from any furnace smelting, roasting or calcining pyrite ores or sulfur bearing materiels; end second, to produce .a very eficient and cheat process whereby the reactions are caused to take place completely rapidly. We have attained these objects by the method described, illustrated end claimed in the following specification gases in which sulfur exists in en oxidized condition (for example as sulfur dioxid) are passed through an incandescent layer or body of coke or other similar carbonacecus material, said sulfur compounds are decomposed with a resulting liberation oi elemental sulfur. This reduction may be represented by the known react1onsz- "in order that the reduction of these compounds to elemental sulfur may take .place completely, rapidly and practically, we have found that a high temperature must be maintained within the layer or body of coke or other similar carbonaceous material.

1,000 cent; 91% at 1,100 Gene; 96% at l.,9.00 cent, and 98% at 1,300 cent. Within the limits mentioned, the higher the temperature maintained, the more rapid will be the formation of the elemental sultur. Also the amount of sulfur formed is found to increase in gsrcportion to the length of time during which gases are in contact with the incandescent carbon. In other words, either an increase in the depth of the incandescent mass of carbon through which the geses ass or (a decrease in the velocity or" the gases in gxassimg through such an incandescent mess or carbon will result in a greater percentage of elemental sulfur formed.

ilect of the electric current in passing through a mass of highly heated particles or carbon, er cmbonaceous material, or through the vapor of carbon, as in the case of the electric arc. By the proper regulation or". the amount of electric current, so used, any desired degreeof temperature can be maintained, while at the same time the amount of carbon required for the reduction can be proportioned and supplied according to the amount of oxygen present in the sulfur gases treated, whether such oxygen exists in a free state or combined with the sulfur. ln other t-vcrds, we are enabled to regulate the temperature to the most eilicient and practicable point, quite independently of the rate of heat-development by the combustion of the carbon. We accomplish this by supplying the increment of heat Whichis neces sary to secure the practically complete reduction of the sulfur (lioxid, from a source independent of the oxidation of the carbon by the gas-stream. Now, therefore, instead of dependin solely upon the heat of reaction, as has laeen done heretofore, which 1s not sufiicient in itself to maintain such elevated temperatures and other conditions re.- quired, and in order to produce and maintain such .elevated temperatures and other 7 conditions, we employ the heating andpossibly electrolytic effects of an electric current by passing it through a mass of highly heated particles of carbon, or carbonaceous material, in the presence of the gases or in contact therewith, such periodsof contact being uniformly maintained for a definite period of time at the temperature at which the reduction of the sulfur'dioxid is nearly quantitative, or a sufficient approximation thereto for practical purposes; By our process then we produce an effect which we believe otherwise to be impossible. Our new process otherwise consists in subject -ing the gas to the combined actionyof a fur from its compounds by subjecting the gas to a temperature of 1300 cent. produced by passing the electric current.

through a mass of incandescent coke in the presence of the gas or in contact therewith,

the gas and coke being in contact for a period of five seconds time, more or less, preceding condensation of. the resulting product.

The process may be carried into effect by a furnace such-as that represented in the accompanying sheet of drawing forming a part of this specification in which the figure shows a central vertical-section of an electric furnacein which A designates a furnace shaft having a grate B at the bottom; A gas inlet C is provided'below the grate B and a gas exit D above the same; 'A body of coke particles is placed on the grate filling'the furnace shaft up to the gas exit so that a current of gas passing in at the inlet will pass up through the coke and out to a condenser (not shown). The top of the furnace shaft is open and is provided with.

a removable cover-E for fillin the furnace w th fine particles of coke. flue is provided (but not shown) whereby the gas 1s drawn in at the inlet and up to the sulfur condenser (not shown) from which the products of combustion are discharged into a chimney (not shown). The electric circuit comprises conductors terminating in electrodes F which in the present instance enter through suitable openings at opposite sides of the furnace body inwhich suitable porcelain insulation tubes F are placed to cause the electric current passing from one electrode to the other to pass through the body of coke in thefurnace.

It will be understood that the size and shape ofthe furnace and its walls, the location and size of the inlet and outlet openings for the admission and escape of the gases, and whether said openings are so arranged as to cause the gases to pass verticallyflupward or downward or to pass horizontally through the carbon, the arrangement of the grates the sizes of the electrodes, the material of which they are composed, the method of adjusting and feeding of. the furnace have no bearing on our vmetallurgical or chemical process, other than to show one way by'which it is carried into effect and may be materially modified without in the least departing from the scope of our invention. The electric current employed to producethe required effect may be either direct or alternatmg.

We claim 1. The process of reducing sulfur dioxid I to elemental sulfur, which consists in maintaining the sulfur. dioxid in contact with incandescent carbon for a predetermined period, and supplying the increment of heat necessary to secure practically complete reduction of the sulfur dioxid from a source independent of the oxidation of said carbon.

2. The process of reducing sulfur dloxld' ,to elemental sulfur, which consists in main-.

taining the sulfur dioxid in contact with incandescent carbon for a predeterm1n ed period, and supplying electrically. the 1ncrement of heat necessary to secure practldioxid.

3. The process to elemental sulfur, which consists in pass-' ing the sulfur dioxid through a bed of 1ncandescent carbon and maintaining 1t in contact therewith for a predetermmed period, and supplying the increment of heat cally complete reduction of the sulfur.

of reducing sulfur dioxid descent carbon for a predetermined period,

sary to secure practically complete reduction of the sulfur dioxid from asource mand supplying the increment of heat necesi dependent of the-oxidation ofsaid carbon.

5. The process of reducing sulfur dioxid to elemental sulfur, which consists'in maintaining the sulfur dioxid, commingled with atmospheric oxygen, in contact with incandescent carbon fornprede tered periofi and supplying electrically the increment 0% to secure practically .comn of the sulfur dioxid.

heat necessary plete reducti meeeie 6. The process of reducing sulfur dioxiol to elemental sulfur, which consists in pess' ing the sulfur dioxid, commin led with et I,

eci of incein descent carbon and melntztining it in conmospheric oxygen, through a tact therewith for a predetermined period,

and supplying the incremen qulred to secure practically t of heat reeconiplete re= memes to this duction of the sulfur &ioxid by electric current through mid 'wtestimonywhereof, we have siped our @5 specification in the presence of two subscribing witnesses this seventh day of June 1913,-at Isabelle, Tenne.

F018 OREAUX. c r .z WILLIAM RENWIGK.

itnesses JUL. Serrmerom G. rF g v 

